Printe Preview: add 'More/less options' button and make non-essential sections collapsible

chrome/browser/resources/print_preview/settings/margin_settings.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 cr.define('print_preview', function() {
   'use strict';
 
   /**
    * Creates a MarginSettings object. This object encapsulates all settings and
    * logic related to the margins mode.
    * @param {!print_preview.ticket_items.MarginsType} marginsTypeTicketItem Used
    *     to read and write the margins type ticket item.
    * @constructor
-   * @extends {print_preview.Component}
+   * @extends {print_preview.SettingsSection}
    */
   function MarginSettings(marginsTypeTicketItem) {
-    print_preview.Component.call(this);
+    print_preview.SettingsSection.call(this);
 
     /**
      * Used to read and write the margins type ticket item.
      * @type {!print_preview.ticket_items.MarginsType}
      * @private
      */
     this.marginsTypeTicketItem_ = marginsTypeTicketItem;
   };
 
   /**
    * CSS classes used by the margin settings component.
    * @enum {string}
    * @private
    */
   MarginSettings.Classes_ = {
     SELECT: 'margin-settings-select'
   };
 
   MarginSettings.prototype = {
-    __proto__: print_preview.Component.prototype,
+    __proto__: print_preview.SettingsSection.prototype,
 
-    /** @param {boolean} isEnabled Whether this component is enabled. */
+    /** @override */
+    isAvailable: function() {
+      return this.marginsTypeTicketItem_.isCapabilityAvailable();
+    },
+
+    /** @override */
+    hasCollapsibleContent: function() {
+      return this.isAvailable();
+    },
+
+    /** @override */
     set isEnabled(isEnabled) {
       this.select_.disabled = !isEnabled;
     },
 
     /** @override */
     enterDocument: function() {
-      print_preview.Component.prototype.enterDocument.call(this);
-      fadeOutOption(this.getElement(), true);
+      print_preview.SettingsSection.prototype.enterDocument.call(this);
       this.tracker.add(
           this.select_, 'change', this.onSelectChange_.bind(this));
       this.tracker.add(
           this.marginsTypeTicketItem_,
           print_preview.ticket_items.TicketItem.EventType.CHANGE,
           this.onMarginsTypeTicketItemChange_.bind(this));
     },
 
     /**
      * @return {HTMLSelectElement} Select element containing the margin options.
@@ skipping 16 matching lines @@
               select.selectedIndex);
       this.marginsTypeTicketItem_.updateValue(marginsType);
     },
 
     /**
      * Called when the print ticket store changes. Selects the corresponding
      * select option.
      * @private
      */
     onMarginsTypeTicketItemChange_: function() {
-      if (this.marginsTypeTicketItem_.isCapabilityAvailable()) {
+      if (this.isAvailable()) {
         var select = this.select_;
         var marginsType = this.marginsTypeTicketItem_.getValue();
         var selectedMarginsType =
             /** @type {!print_preview.ticket_items.MarginsType.Value} */ (
                 select.selectedIndex);
         if (marginsType != selectedMarginsType) {
           select.options[selectedMarginsType].selected = false;
           select.options[marginsType].selected = true;
         }
-        fadeInOption(this.getElement());
-      } else {
-        fadeOutOption(this.getElement());
       }
+      this.updateUiStateInternal();
     }
   };
 
   // Export
   return {
     MarginSettings: MarginSettings
   };
 });